(355h) Hydroxylated Soybean Lecithin for Crude Oil Spill Remediation

2015 American Institute of Chemical Engineers Annual Meeting

Salt Lake City, UT. November 8-13, 2015

Hydroxylated Soybean Lecithin for Crude Oil Spill Remediation

Emmanuel Nyankson and Ram B. Gupta

Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA

The accidental release of natural crude oil into our marine waters and its subsequent effect on the environment is one of the major problems that the environmental protection agencies of most countries worldwide have to deal with. The application of chemical dispersants is one of the few feasible response measures for minimizing the impact of a large oil spill at sea. Effective use of dispersants can accelerate oil biodegradation by naturally occurring microorganisms and prevent the oil spill from coming ashore and damaging sensitive coastal ecosystems. The traditional chemical dispersant formulations used in combating oil spills are made up of mainly hydrocarbon solvents, petroleum derived surfactants and some additives. The toxicity of these chemical dispersants has necessitated the search for alternative dispersant formulations that are environmentally benign. Soybean lecithin, a well-known surface active agent in the food industry has excellent emulsification property; it is biodegradable, less toxic and ecologically acceptable. In this study, soybean lecithin was hydroxylated by reacting it with hydrogen peroxide in the presence of lactic acid as a catalyst. The hydroxylated soybean lecithin was solubilized in water and it effectiveness in dispersing Texas crude oil was examined with the U.S. EPA’s baffled flask test. The oil-water interfacial tension of hydroxylated soybean was determined with the pendant drop method. The preliminary results showed that, at a surfactant-to-oil ratio (SOR) of 37.5 mg/g (0.0375), the dispersion effectiveness of the hydroxylated soybean lecithin was 92 vol. % compared to 55.6 vol. % for the unhydroxylated soybean lecithin. 

The soybean lecithin will be fractionated into ethanol soluble fraction (Phosphatidylcholine) and ethanol insoluble fraction (Phosphatidylinositol). These fractions will then be hydroxylated and the effect of hydroxylation on oil-water interfacial tension, critical micelle concentration, emulsion droplet size and dispersion effectiveness examined. The stabilization mechanism of the oil-water emulsions by the hydroxylated soybean lecithin will also be studied on molecular level.